The Cancer and Leukemia Group B (CALGB) Statistical Center located at Duke University has primary responsibility for all statistical, data management, computing, and related activities for the CALGB. Faculty and staff statisticians collaborate closely with study chairs, committee chairs, and other investigators on the design, conduct, analysis, and reporting of all clinical trials and other studies conducted by the CALGB. The data management center (DMC) is part of the Statistical Center and has the central responsibility for data quality control and database administration. All data forms are sent to the DMC for editing, verification, and entry into the central database system. In addition to the scientific data, the database system also includes the administrative data necessary for managing the CALGB so that a single integrated database is used for all reports and analyses.